<!DOCTYPE html>
<html lang="en">
<head>
  <meta charset="UTF-8">
  <meta name="viewport" content="width=device-width, initial-scale=1.0">
  <meta http-equiv="X-UA-Compatible" content="ie=edge">
  <title>css背景位置</title>
  <link rel="stylesheet" href="./self.css">
</head>
<body>
  <div class="pic pic1">border-box</div>
  <br><hr><br>
  <div class="pic2 pic">padding-box</div>
  <br><hr><br>
  <div class="pic3 pic">content-box</div>
  <br><hr><br>
  <div id="colorful_word">
    ☯
  </div>
</body>
</html>